一种无腹筋混凝土梁受剪承载力计算的新方法  

Novel calculation method for shear capacity of RC beams without web reinforcement

作　　者：郑开启[1] 刘钊[1] 孟少平[1] 秦顺全[1,2] Zheng Kaiqi Liu Zhao Meng Shaoping Qin Shunquan(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing 210096, China China Railway Major Bridge Reconnaissance and Design Institute Co. , Ltd. , Wuhan 430050, China)

机构地区：[1]东南大学混凝土与预应力混凝土结构教育部重点实验室,南京210096 [2]中铁大桥勘测设计院集团有限公司,武汉430050

出　　处：《东南大学学报（自然科学版）》2017年第2期362-368,共7页Journal of Southeast University：Natural Science Edition

基　　金：交通运输部建设科技资助项目(2014318494020);江苏省交通运输科技资助项目(2014Y01)

摘　　要：为了提高无腹筋混凝土梁特别是大尺寸、低纵筋率的无腹筋梁的受剪承载力预测精度,提出了一种无腹筋混凝土梁受剪承载力计算的新方法.首先,假定剪力主要由无腹筋梁的混凝土受压区承担,并根据其破坏模式将混凝土受压区细分为剪压区和斜拉区2个部分;其次,通过分析剪压区和斜拉区的破坏机理,建立抗剪贡献的计算公式;然后,通过合理简化和理论推导,确定受压区高度、剪压区高度等主要参数的取值;最后,在考虑尺寸效应的基础上,建立无腹筋混凝土浅梁的受剪承载力解析公式,该公式具有明确的物理涵义,能够反映混凝土强度、纵筋率、剪跨比以及尺寸效应等主要因素的影响.试验结果表明,相比于现行主要规范公式,所提公式的预测精度和预测稳定性均有明显提高.A novel calculation method was proposed to improve the prediction accuracy of the shear capacity of reinforced concrete（ RC） beams without web reinforcement,especially for the beams with large size and lowlongitudinal reinforcement ratio. First,the shear force was assumed to be mainly balanced by the concrete compression zone,which can be further divided into two regions,including the shear compression zone and the diagonal tension zone,by the failure modes. Secondly,the failure mechanisms in the shear compression zone and the diagonal tension zone were analyzed,and the corresponding shear contribution formulas were established. Then,with rational simplification and theoretical derivation,the main parameters such as the height of the compression zone and the height of the shear compression zone were determined. Finally,the analytical formula of the shear strength of the RC beams without stirrups was formed with consideration of the size effect. This formula has a clear physical meaning and can reflect the influences of the major shear parameters such as the concrete strength,the longitudinal reinforcement ratio,the ratio of the shear span to the depth,the size effect,and so on. The experimental results showthat the proposed formula provides higher prediction accuracy and stability compared with the shear formulas in the main existing codes.

关 键 词：钢筋混凝土梁 受剪承载力 剪压区 斜拉区 尺寸效应 

分 类 号：TU375.1[建筑科学—结构工程]